MeasureElephantPopulations

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Anthropology

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Apr 3, 2024

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Name: __Natalee Adkins___________________________ (15 points) Introduction Due to habitat loss and hunting, African elephants and many other animals are in danger of dying out. Determining where these animals live and how large their populations are can help us decide where to focus conservation efforts. Using an interactive tool, you will simulate methods that scientists have used to determine elephant population sizes. The tool will store the data you collect in several tables. You’ll use these tables to make sense of the data and help explain why these methods are important — not just for elephants but for other populations too. PROCEDURE Follow the instructions and complete the questions as you work through this worksheet. First, open the Elephant Census interactive tool. You’ll use this tool to simulate some of the methods that scientists used for the Great Elephant Census: a large-scale survey that counted elephants across Africa. Before engaging with the tool, review all of the content in the “Introduction” section, which includes: • an 8-minute video on the Great Elephant Census • a “Measure Area” section overview and instructions • a “Count Elephants” section overview and instructions Return to this section whenever you need clarification for how to engage with the sections of the tool. PART 1: The Great Elephant Census After watching the video in the “Introduction” section, answer the following questions. Be prepared to share your ideas. 1. Why do you think it was important for scientists to do the Great Elephant Census? Elephants are endangered by poaching and habitat loss. Their figures are unknown, so it was important for them to try to get an accurate number to estimate how endangered they are. It will form the basis for planning ongoing conservation efforts and for studying elephant ecology. Consider the following questions based on your ideas in the table. You don’t have to answer these questions now, but you will revisit them at the end of this worksheet. • Why do scientists use sample counts instead of a total count of all elephants in Africa? • If scientists did a total count of all elephants in Africa, what could happen in the time between starting and finishing that would impact elephant population sizes?

2. In the following table, list the advantages and disadvantages of using a sample count vs. a total count to determine the size of a population. Method Advantages Disadvantages Sample count Most reliable to estimate over large areas at an effective cost. Takes less time. Much more difficult to set up. Less precise. Total count Every individual is accounted for and is more precise. Not practical on a massive scale. Population count can change any second. PART 2: Measure Area Navigate to the “Measure Area” section of the interactive tool, which will open a map showing a model of the transects and strips in the video. Observe the map and familiarize yourself with the parts of this model. • Transects are the lines that the airplane flies along. There are two transects of different lengths, labeled Transect A and Transect B. • Strips are the areas around a transect that are sampled — that, the areas in which elephants are counted by people flying along the transect. Each transect has two strips with the same dimensions, labeled Strip 1 and Strip 2. Now you’ll measure the dimensions (length and width) of a strip for each transect, then the entire map. To make the measurements, follow the prompts in the dialogue box in the middle of the map . Additional instructions are provided in the “Introduction” section and are also copied below: • Make a measurement by placing a start and end point using your mouse/finger or keyboard arrow keys. o Place a point by clicking/tapping directly on the map. Or, tab to or click on the crosshair target icon and use the arrow keys to move it into place. Press the Enter key to place a point. o After placing the second point, a line will be drawn. • If you make a mistake placing your points, you can use the “Undo Last” button. • When you are happy with your measurement, lock it in by selecting the “Submit” button to add it to the sidebar table. • To reset individual measurements, select the X icon, then select “Reset Cell” in the sidebar table’s cell you wish to reset. You will be prompted to measure again. • When you have completed all measurements and the sidebar table is populated, the “Send to Data Tables” button will become active. • Switch to the “Data Tables” section to view data and other calculations. • To reset the entire “Measure Area” tool, select the “Reset” link at the top of the tool’s sidebar. Note: Resetting the sidebar table will clear the “Data Tables” values associated with this tool. Note that since Strip 1 has the same dimensions as Strip 2 for each transect, the table will automatically use your Strip 1 measurements for Strip 2. The table will also show a “Total” for each transect that combines the widths of Strips 1 and 2. This represents the total area around the transect that was sampled. Answer the following questions to help make sense of the data. Page 2 of 4

3. Data Table 1 shows the total transect area , which is the area sampled around Transect A added to the area sampled around Transect B (in other words, the areas of all the strips added together). What is the purpose of adding these areas together? To get the total area sampled and to calculate density you need to add the transect areas together. 4. How could you use the number of elephants in the transect areas to estimate the number of elephants in the total map area? You must find the density of elephants in the transect areas and then multiply that by the total map area to estimate how many elephants are on the whole map. PART 3: Count Elephants Navigate to the “Count Elephants” section of the interactive tool. This will show the same map as in the “Measure Area” section, but now with icons representing two types of elephants, tusked and tuskless, as shown in Figure 1: • Tusked elephants are those with tusks (long front teeth that grow outside their mouths). These elephants can use their tusks to fight, gather food, and dig holes for water. However, they may be killed by poachers (illegal hunters) who want to take their tusks for ivory. • Tuskless elephants are those without tusks. Being tuskless is a natural, but usually rare, trait that some African elephants are born with. Figure 1. Icons representing a tusked elephant (left) and a tuskless elephant (right). Now you’ll count the numbers of each type of elephant around each transect, then across the entire map. To complete the counts, follow the prompts in the dialogue box in the middle of the map . Additional instructions are provided in the “Introduction” section and are also copied below. • Hover, long press, or tab to the elephants to get info about them (e.g., Not Counted, Tusked Elephant, Inside Transect A). • To count the tusked and tuskless elephants within a transect, click, tap, or tab/enter to select the elephants to add them to the “Current Count.” Repeat the action to deselect the elephant, or use the “Undo Last” button. o Tip: Use the keyboard shortcut Alt + A for “All Elephants.” o Remember to count elephants in both strips for each transect. • When you are happy with your current counts, select the “Submit” button to add them to the sidebar table. • To reset individual group counts, select the X icon, then select “Reset Cell” in the sidebar table’s cell you wish to reset. You will be prompted to count the group again. Page 3 of 4

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• You will then be prompted to count the next group. When you have completed counting all four groups and the entire population, the “Send to Data Tables” button will become active. • Switch to the “Data Tables” section to view data and other calculations. • To reset the entire “Count Elephants” tool, select the “Reset” link at the top of the tool’s sidebar. Note: Resetting the sidebar table will clear the “Data Tables” values associated with this tool. Answer the following questions to help make sense of the data. 6. What might cause the size of the elephant population to change? Elephants dying or giving birth and how many elephants enter or leave the population. 7. Consider the information on tuskless elephants in your Data Table 2. a. What percentage of elephants in the transect areas were tuskless? A= 5/9= 55.6% B= 1/5= 20% Total= 6/14= 42.9% b. What might studying this percentage over time tell us about the elephant population? It can help us understand why it's declining and find potential causes and solutions before they become extinct. PART 4: Data Tables for Elephant Population Densities Return to the “Data Tables” section for the Elephant Census tool. Go to Data Table 3 , which uses the data you collected in Data Tables 1 and 2 to make some additional calculations. Answer the following questions to help make sense of these numbers and why they are important. You can select the “i” icons in the table to learn more about certain parts. 8. Based on Data Table 2: a. What was the elephant population density (elephants/km 2 ) for Transect A? 9/11 km2 = 0.8 elephants/km2 b. What was the elephant population density (elephants/km 2 ) for Transect B? 5/13.2 km2 = 0.4 elephant/km2 Page 4 of 4

MeasureElephantPopulations

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